Addition of Organomanganese Reagents to Enones

It should be emphasized that with less reactive Michael acceptors such as enones, organomanganese reagents generally lead to a mixture of 1,4-addition product and reductive /3-dimerization products. In addition, the formation of the 1,2 addition product is sometimes also observed. The 1,4 addition product is only exceptionally obtained as a main product. 

On the other hand, the reaction sometimes gives the reductive -dimeiization product in good yields [34]. 

The presence of copper salts as a catalyst deeply influences the course of the reaction since the conjugate addition product is very often formed exclusively in high yields. This Cu-catalyzed 1,4addition reaction takes place under mild conditions (THF, 0 C). 

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